Hi,
The 12 core profiles I think is a great step forward. Four of them are coupled to the altitude where the beans have been grown and two variants of each RTD or Rest depending when it's best to drink the coffee.
Scott Rao lists a lot of factors affecting the heat in the beginning of the roasts in his book "The Coffee Roasters Companion".
Altitude: The theory is that altitude affects the density of the bean and a higher altitude gives a denser bean.
Batch size: A bigger batch needs more heat in the beginning but the batch size is not possible to change very much with the KL and it's possible to treat it as a constant if you keep the same batch size.
Bean size: A larger bean needs more energy in the beginning and maybe it should be treated as a bean from a high altitude even if it's grown on a lower altitude? Magaroype is an example. A small Ethiopian bean even if it's grown on a high altitude and especially if it's naturally processed may not tolerate high temperatures in the beginning.
Bean processing method: Fully washed beans tolerates hotter temperatures in the beginning than naturally processed beans and the process may also affect moisture content.
Moisture content: This is also a factor and a moister bean may need more heat in the beginning.
Is it really so that altitude is the most important thing when you choose a profile? Isn't it to simplify it too much? Don't you have to weigh in other factors also? Could it be that a small Ethiopian natural is better roasted with one of the 0-1200 profiles than with the 2000-2700 m profiles? I don't say that it is I'm just raising the question.
I think it could be to a good help if this became more clear. What do the community think about this and do you have any experience of using "altitude profiles" out of the book?
There are also other profiles both from the community and from Kaffelogic but it's not always explained what beans that suit them the best.
Altitude but...
-
kaffelogic
- Site Admin
- Posts: 505
- Joined: Thu 18 Oct, 2018 9:38 am
- x 73
- Contact:
Re: Altitude but...
A brief answer: the 12 core profiles are a great simplification. In many circumstances they do work well and provide users with the ability to achieve a great result quickly. However they are a starting point and it is definitely worth trying the neighboring altitude profiles especially if the results are not quite what you are expecting.
On the whole commodity coffees will respond well to the core profiles, while specialty coffees can be a little more unpredictable and may benefit from wider experimentation. As you have pointed out there are many factors and the process of perfecting a profile for a given batch of coffee can be complex. There are no simple answers in the quest for perfection.
The core profiles provide a system that removes the complexity and therefore enables the average user to get started with choosing optimal roast profiles. For many users the core profiles will be all they want.
We encourage green bean vendors to provide guidance and to supply optimal Kaffelogic profiles for coffee that they sell, especially for the more expensive of the specialty coffees, however it will take some time until this practice becomes widespread. There are also Green Bean Reviews which is an opportunity for users to share their experience with aligning beans and profiles on a per-origin basis.
I encourage other users to respond and share your experience of the core profiles, and other profiles available elsewhere on this forum.
On the whole commodity coffees will respond well to the core profiles, while specialty coffees can be a little more unpredictable and may benefit from wider experimentation. As you have pointed out there are many factors and the process of perfecting a profile for a given batch of coffee can be complex. There are no simple answers in the quest for perfection.
The core profiles provide a system that removes the complexity and therefore enables the average user to get started with choosing optimal roast profiles. For many users the core profiles will be all they want.
We encourage green bean vendors to provide guidance and to supply optimal Kaffelogic profiles for coffee that they sell, especially for the more expensive of the specialty coffees, however it will take some time until this practice becomes widespread. There are also Green Bean Reviews which is an opportunity for users to share their experience with aligning beans and profiles on a per-origin basis.
I encourage other users to respond and share your experience of the core profiles, and other profiles available elsewhere on this forum.
Re: Altitude but...
Thank you for the reply!
I'll try to explain a little more what I'm after. I want and need more information what thoughts and decisions that are behind the different profiles. Altitude does affect the density of the beans and a denser beans needs more heat in the first half of the roast. A bigger size of a bean does also need more heat or energy in the beginning and a smaller bean less. A naturally processed bean may need a gentler start and if it's also small then...A natural processed Ethiopian is often small and naturally processed but high grown.
I have compared some profiles and "Classic" seems to be one of the profiles that has most energy in the first half of the roast. What beans is it best suited for? All "Altitude" profiles have a slower start but the profiles meant for higher altitudes seem to have more energy in the beginning.
I went to "The green beans reviews" and we don't have so many reports there by now but I hope there will come more. One member theiguanaoz has published two different reviews both of Colombian beans and he seems to like the result for espresso. The first is a Colombian Supremo that is supposed to be a bigger bean (screen 17) and he used "Firestarter". When I compare "Firestarter" with the altitude profiles and the Classic profile it does have a rather gentle start with rather low energy in the beginning of the roast. In the second review he has published he used the Classic profile with a Colombian Excelso that is a smaller bean (screen 14-16). He seems to like the result from this roast even better! This is a little contradictory! Maybe he should have reversed the profiles or maybe some other profile could have been even better?
At my stage of learning "The Art Of Roasting Coffee" I've become a little confused what to look for in the different profiles available and what profile is best for the bean I'm going to roast. It had been nice if the intention with the profiles had been better explained and what kind of bean they are meant for. I have not yet come to the stage where I can make my own profiles.
I'll try to explain a little more what I'm after. I want and need more information what thoughts and decisions that are behind the different profiles. Altitude does affect the density of the beans and a denser beans needs more heat in the first half of the roast. A bigger size of a bean does also need more heat or energy in the beginning and a smaller bean less. A naturally processed bean may need a gentler start and if it's also small then...A natural processed Ethiopian is often small and naturally processed but high grown.
I have compared some profiles and "Classic" seems to be one of the profiles that has most energy in the first half of the roast. What beans is it best suited for? All "Altitude" profiles have a slower start but the profiles meant for higher altitudes seem to have more energy in the beginning.
I went to "The green beans reviews" and we don't have so many reports there by now but I hope there will come more. One member theiguanaoz has published two different reviews both of Colombian beans and he seems to like the result for espresso. The first is a Colombian Supremo that is supposed to be a bigger bean (screen 17) and he used "Firestarter". When I compare "Firestarter" with the altitude profiles and the Classic profile it does have a rather gentle start with rather low energy in the beginning of the roast. In the second review he has published he used the Classic profile with a Colombian Excelso that is a smaller bean (screen 14-16). He seems to like the result from this roast even better! This is a little contradictory! Maybe he should have reversed the profiles or maybe some other profile could have been even better?
At my stage of learning "The Art Of Roasting Coffee" I've become a little confused what to look for in the different profiles available and what profile is best for the bean I'm going to roast. It had been nice if the intention with the profiles had been better explained and what kind of bean they are meant for. I have not yet come to the stage where I can make my own profiles.
-
kaffelogic
- Site Admin
- Posts: 505
- Joined: Thu 18 Oct, 2018 9:38 am
- x 73
- Contact:
Re: Altitude but...
The intention behind the profiles is simple. They were designed to provide a small set of profiles accompanied by a conceptually easy way to select the appropriate profile for the beans and intended use of the beans. Of the many different factors that can be taken into consideration, such as individual tastes, intended use, bean size, bean density, processing method, growth latitude, growth altitude, varietal, and grade, we determined that growth altitude provided the most practicable factor around which to design the profiles. This was a judgement based on years of coffee roasting experience. Accordingly the coffees of the world were grouped in altitude bands, and then profiles developed for each band. They were developed to work with all of the coffee grown in that band around the world. Naturally they are not optimized for every different coffee from that band, but generalised so that they work with the majority of coffee from that band. They provide a solid go-to starting point for all coffee from that band. Our advice is to start with the 12 core profiles and work with them until you feel you have reached their capacity to provide you with what you are seeking. That is, don't skip around all over the place, but really dig into what the core profiles can do for you - exploring the neighboring altitude bands for any given coffee, but focusing on tuning the roast levels.
It is true that profiles can be (even should be) tuned to accommodate and optimise for any or all of the factors I have mentioned above, but teaching you how to do that is a full course in coffee roasting and profile design, not a forum post. For a starting point, let altitude be your guide regardless of other factors. That is the intent of the altitude profiles.
Some time in the new year Wayne will chip in on this subject and give you just a little more detail about the principles, but for every rule of thumb there is also a different and contradictory rule of thumb. The reason is that there are potentially thousands of chemical reactions, some of which are exothermic, some endothermic in coffee roasting. Heat flow depends on both specific heat and thermal conductivity which are interrelated and changing dynamically during a roast. So the fact is there are no easy answers. Almost all knowledge to do with flavour has been developed heuristically. There is no one consistent theory of roasting or set of universal principles. In the end your taste buds must be your guide and you must be open to experimenting. Wayne will help you with some principles that he has developed, but you must integrate those principles with your own personal knowledge base, which you can only build by experimenting and tasting.
Roast the coffee, drink the coffee, and have fun.
It is true that profiles can be (even should be) tuned to accommodate and optimise for any or all of the factors I have mentioned above, but teaching you how to do that is a full course in coffee roasting and profile design, not a forum post. For a starting point, let altitude be your guide regardless of other factors. That is the intent of the altitude profiles.
Some time in the new year Wayne will chip in on this subject and give you just a little more detail about the principles, but for every rule of thumb there is also a different and contradictory rule of thumb. The reason is that there are potentially thousands of chemical reactions, some of which are exothermic, some endothermic in coffee roasting. Heat flow depends on both specific heat and thermal conductivity which are interrelated and changing dynamically during a roast. So the fact is there are no easy answers. Almost all knowledge to do with flavour has been developed heuristically. There is no one consistent theory of roasting or set of universal principles. In the end your taste buds must be your guide and you must be open to experimenting. Wayne will help you with some principles that he has developed, but you must integrate those principles with your own personal knowledge base, which you can only build by experimenting and tasting.
Roast the coffee, drink the coffee, and have fun.
-
kaffelogic
- Site Admin
- Posts: 505
- Joined: Thu 18 Oct, 2018 9:38 am
- x 73
- Contact:
Re: Altitude but...
Thank you very much Chris for a thorough answer and Merry Christmas!
This last link was exactly what I'm thinking of and I was going to share it. I've made a comparison of the two profiles and how they differ. The 1500-2000 m is "kinder" in the beginning of the roast and seems to be better suited for the more sensitive Ethiopian Natural. In the picture the 1500-2000 m is the weaker thinner line.
If the intention and the thinking behind a profile are more clearly explained then I think it makes it easier for the not so advanced roaster to make adjustments or maybe choose another profile. I still think the core profiles are a great and important step forward!
I may want to open another question and maybe there should be a separate thread for that. I try to aim for a DTR between 20-25% as recommended by Scott Rao. My experience is that only very few profiles can fill that criterion. It could be the calibration of my machine. I prefer medium dark/dark for espresso and the profile that works for me is Steady&Dark II. Most other profiles will be too light and acid and not well developed in the recommended DTR span. Steady&Dark II works best with lower altitude and not so dense beans but I've not succeded to get good results with denser beans.
This last link was exactly what I'm thinking of and I was going to share it. I've made a comparison of the two profiles and how they differ. The 1500-2000 m is "kinder" in the beginning of the roast and seems to be better suited for the more sensitive Ethiopian Natural. In the picture the 1500-2000 m is the weaker thinner line.
- 2000-2700m Rest_compared_1500-2000Rest.png (60.47 KiB) Viewed 8623 times
I may want to open another question and maybe there should be a separate thread for that. I try to aim for a DTR between 20-25% as recommended by Scott Rao. My experience is that only very few profiles can fill that criterion. It could be the calibration of my machine. I prefer medium dark/dark for espresso and the profile that works for me is Steady&Dark II. Most other profiles will be too light and acid and not well developed in the recommended DTR span. Steady&Dark II works best with lower altitude and not so dense beans but I've not succeded to get good results with denser beans.